# Parse a CSV string of songs and return the list (position, originalChartDate, artist, title)
import unittest


def parse_songs(songs):
    songs_list = []
    for song in songs.split('\n'):
        song = song.split(',')
        if len(song) == 4:
            songs_list.append(song)
    return songs_list

# using unittest to test the parse_songs function
class TestParseSongs(unittest.TestCase):
    def test_parse_songs(self):
        songs = '1,2,3,4\n5,6,7,8'
        songs_list = parse_songs(songs)
        self.assertEqual(songs_list, [['1', '2', '3', '4'], ['5', '6', '7', '8']])